Electric grinder



c.' H. BEACH. ELECTRIC GRINDER;

7 APPLICATION may HAY 23, m9. 1,391,039, 'Patentdsept. 20,1921.

2 SHEETS-SHEET",

@XMM" C. H. BEACH. ELEcTm'c snmmzn. APPLICATION FILED IAY 23. I919.

PatentodSept. 20, 1921.

2 SHEETS-SHEET 2- UNITED STATES PATENT OFFICE.

CHESTER H. BEACH, OI CINE, WISCONSIN, ASSIGNOR TO WISCONSIN ELECTRIC GOIPANY, A CORPORATION 01 WISCONSIN.

merino eamnnn.

' Application ma Kay 2a, 1919. amino. 299,315.

To all whom it may concern:

Be it-knownthat I, CHESTER H. BEACH, a citizen of the United States, residin at Rae cine, in the count of Racine and tate of Wisconsin, have lnvented certain new and useful Improvements in Electric Grinders, of which the following is a specification.

My invention relates to improvements in universal electric grinders.

One object of the invention is to provide a high speed grinder comprising a motorad- 'ustable with reference to its sup ort, wherey said motor may beswung to different positions of adjustment to prevent interference with the work piece being ground.

Another object is to'provide a high speed grinder which may rotate at a very high rate of s eed without substantial vibration,

where y the grinding wheel may grind with extreme accuracy.

A further object is to provide means for adjustingthe belt tension and maintaining the proper tension regardless of the adjustment of the motor with reference to its suport. p In the accompan ing drawings I have illustrated a practica and successful embodi ment of the invention. Theinvention may be embodied in other forms, however.

In the drawings- Fi re 1 is a front elevation of the grin er;

Fig. 2 is a side elevation thereof, certain parts being broken away to disclose the construction;

Fig.3 is a front elevation of the motor,

. the supporting means therefor being shown in section; I a

Fig. 4 is a partial end elevation and artial section taken on the line 4-4 of ig'. 1; and

Fig. 5 is an elevation of one of the grindin tools.

he motor 1 may be of any suitable type, but is preferaigly provided with a very accurately balanc armature, whereby vibration is avoided. The armature is mounted on the usual armature shaft 2, the'latter carryin a driving pulley 3 on one end thereof. A It 4 drives a large pulley 5, the latter being mounted on the reduced and 6 of the drivmg spindle 7 of the grinder. Said s indle is provided with ball bearings 8, 9, t e outer race-ways of which are a snug fit within the housing 10 and are prevented sition of the motor wit from turning therein by means of studs 11, which project into a groove 12 in each outer race-way. The said housing constitutes a ortion of the base member 13, which latter as a dove-tailed sliding connection with the supporting member 14, the latter being carried by the plate 15, to which it is secured by studs 16 passingthrou'gh elongated slots in said plate, thereby providing for a certain adjustment relatively. Said plate, in turn, is carried by a supporting arm 17, to which it is rotatably secured by a stud 18, said arm being arranged to be mounted in the tool (post 19 of a' lathe, for example, and

being a justable therein. The motor 1 is ing secured thereto b studs 21 and cushioned by bushings. 22, ma e preferably of rubber, whereby such slight vlbration of the motor as may exist is nottransmitted to the housing 10 and the grinder spindle 7. As a result of this arrangement and of the balancing of the motor armature an unusually smooth running driving s indle results.

The cradle 20 is provi ed with an apertured lug 23, which is received between a pair of ears on a cylindrical member 25, a rOd 26 passin through alined openings in said parts an constltuting a pivotal support about which the motor ma swing. The porespect to said cylindrical member 25 is adjusted by means of a knurled nut 27 mounted on a screwthreaded s indle 28 and 005 rating,respectively, wit the motor crad e 20 and a projecting lug 29 on said cylindrical casing. By means of this knurled nut the belt tension me. be adjusted, and maintained. The cyllndrical member 25 surrounds a sleeve 30, and is secured thereto, whereby it turns therewith. Said sleeve ,rojects at each end into the housing 10, and is rotatable there- Patented Sept. 20, 1921.-

in. With this arrangement the motor may be swung through a considerable angle and locked in any position of adjustment by means of a locking pin 31, which is held by a spring 32 in any one of a number of radial openings 33 in said rotatable sleeve 30. In Fig. 4 the dotted line position illustrates an ad ustment of the motor of 180 from the full line position. The belt tension is maintained in any sition of adjustment. The grinding whee 34 is mounted .on a suitable tapering spindle 35, which is screwed into a recess in the end of the spindle 7 With this arrangement the grinding wheel may be readily removed and a different one sub stituted.

In Fig. I have illustrated a much 5 smaller grinding wheel 36, adapted for internal grinding, which is mounted on the longer spindle 37 whereby it may project into the recess, the wall of which is'being.

ground, the end being tapered and screwthreaded to enable it to fit into the recess in the driving spindle 7 With the arrange ment described the various grinding wheels inserted in the driving spindle may be adjusted to any desireposition with respect to the member to be ground. An adjustment verticall and in ,any plane horizontally may be effected by means of'the usual, adjustments provided through; the lathe, in the tool post of which the grinder is mounted. In addition, a further adjustment is available by virtue of the dove-tail connection between the base 13 and the suport 14. The piece to be ground may proect in such a manner that the motor 1 would interfere with it and prevent such an adjustment of the grinder as a whole as would enable the grinding wheel to grind the desired surface. Such interference is avoided, however, by the rovision of the means described for swinging the motor to different positions with reference to its support. By virtue of the adjustments described surfaces may be accurately ground which are comparatlvely inaccessible.

I claim 1. A universal grinder comprising a housing, a grinder spindle rotatably mounted therein, and an electric motor mounted to swing about said housing whereby it may be adjusted to different radial positions with reference thereto.

2. A universal grinder comprising a housing, a grinder spindle rotatably mounted therein, an electric motor mounted to swing about said housing whereby it may be adjusted to different radial positions with reference thereto, and means for locking said motor in any position of adjustment.

3. A universal grinder comprising a housing, a grinder spindle rotatably mounted therein, an electric motor mounted to swing about said housing whereby it may be adjusted to different radial positions with reference thereto, a drivin belt from the motor shaft to said spin 1e, and means for adjusting the belt tension.

4. A universal grinder comprising a supporting member, a motor mounted to swing about said member and having an armature shaft, a spindle rotatably mounted in said member, a driving belt from said armature shaft to said spindle, means ivotally supporting said motor with re erence to its rst-mentioned support, means for swing- 65 ing said motor about said pivotal support to adjust the belt tension, and means for maintaining said motor in any position of adjustment with reference to said first support.

5. The combination with a universal grinder, of a supporting member therefor, a sustaining arm secured to said supporting member, a pair of dove-tail members carried by said arm, an electric motor mounted to swing about one of said dove-tail members, and a grinding spindle arranged to rotate at the axis about which said motor swings whereby said spindle may be driven from I said motor in any position of adjustment of the latter without var ing the distance between said driving an driven spindles, and whereby said driven spindle may be adjusted in any desired position and said motor adjusted to avoid interference with the work to be ground.

6. In combination, a housing, a rotatable spindle mounted therein, a barrel within said housing, an electric motor mounted to turn with said barrel, and locking means in said housing for locking said barrel and hence said motor in different positions of adjustment, said motor being also adjusts ab y mounted with reference to said barrel.

7. A universal grinder comprising a supporting base, a grinding spindle supported thereby, and a motor also supported by said base for driving said spindle and movable in a circular path with reference to said spindle as a center.

8. In combination, a su. port, a base carried thereby and adjusta le in more than one direction, a spindle rotatably supported by said base, a motor supported by said base, means for driving said spindle from said motor, and means for adjusting said motor about said spindle as a center.

9. In combination, a supporting base having two projecting parts with alined openings therein, ball hearings in each 0 ening, a grinding spindle mounted in sald ball 110 bearings, an electric motor having a supporting bracket received between said two projecting parts and clearing said spindle, and a belt for driving said spindle from the motor shaft.

10. In combination, a supporting arm to be clamped in the tool post of a lathe or other machine tool, a base adjustably mounted thereon, a member having a slid ing connection with said base and having 102 a pair of spaced cylindrical elements thereon, a cylindrical motor-supporting bracket fitting between said cylindrical elements andmounted to swing about the axis thereof, a driven shaft passing through said cy- 125 lindrical elements, and a shaft on the motor for driving said first shaft.

11. An electric grinder, comprising a base,

a supportin' member having dovetailed en-- gagement t erewith and having alined cy- 130 lindrical projections, a sleeve having a slidi fit vvithin said cylindrical projections, ini fit within said cylindrical projections, a racket secured to said sleeve, a motor a racket secured to said sleeve, a motor carried b said bracket, '9, spring-pressed Q carried b said bracket, and a springplunger or locking said sleeve in prede- 15 5 pressed p unger for locking said sleeve. 1n termlned rotative position within said cypredetermined rotative positions within lindrical projections, and a threaded shaft said c lindrical projections. for adjusting said supporting member and 12. electric grinder, comprisinga base, motor with reference to said base. I a snpportin member having dovetailed en- In testimony whereof, I have subscribed 20 0 gement t erewith and having alined cymy name.

indricalprojections, a sleeve having a slid- CHESTER H. BEACH. 

